ringo wrote:Tommy Cookers wrote:
I don't know why you keep categorizing the MGUH as a load
the existence or non-existence of this conceptual load will be determined by actual MGUH behaviour in use
If it's a boost controller, it's a load. It would be using turbine energy would it not?
the MGUH will be the sharp end of a velocity-controlled 'servo' system
that will continuously (ie progressively and powerfully) control the ''turbo' rpm to be always matched to the engine's needs
this matching is crucial and must be dominant by design
the rpm being ideal for the engine, the only MGUH loading of the engine is exactly what the engine 'wants' to do its designed job
There is a very huge difference with a turbo characteristic and a dc motor characteristic, assuming they are using dc motors. have a look at a dc motor torque vs speed graph. trust me it's not going to be something very easy to do with a gasoline turbo engine.
the 'turbo rpm' demand will be continuously generated ie appropriately time-varied by part-intelligent control
this appropriate time-variation of rpm constitutes the matching of 'turbo rpm' to the engines time-varying needs and capabilities
The turbo doesn't have a demand, it's the MGUH that does. the only demand you will see on the turbo is when it's off boost.
The turbo is the power source.
and the MGUHs essential job is to be the mechanism performing this match (and generate electricity only when appropriate)
It's job is to be a load. And that's all it will do. It's either a load on the turbo, or a load on the battery or energy store when it's spooling the turbo.
seamless and progressively proportionate transition from motoring to generation is what makes a servo-type control system
let's see, but you are only looking on it from a servo side of things. you are not looking on the other half, the half with the power.
of course the rpm control could fail to match rpm eg if there is insufficient or excess stored electrical energy
that sort of thing is an issue in what must be a subordinate area of design, it does not invalidate the concept
there's nothing that's 'not to like' about the MGUH control concept, under these rules
these rules were designed by people who knew what they were doing, and knew what they wanted
All of that resource and investment in research when you only need to put a waste gate on the turbo. In fact that would make the MGUH even more easy to control and give it smoother operation.
What goes through the waste gate, you get it back under braking, simple as that. haha.We're talking a far more responsive engine, to get higher top speeds and better more predictable drivability, for a few drops of fuel. Get it back under braking, the ES will be full most of the time anyway.
I think that you are saying that because boost regulation by MGUH operation as an rpm-controlled 'servo' system accurately responding to a continously varying signal and driving to the turbo rpm ideal for the ICE at that moment is difficult
...... it is both undesirable and impossible
it is clearly desirable to the rulemakers
I think that it is possible
there is no problem with the 'motor' torque curve
any motor type selected for this will have torque always proportionate to the current made available by the drive (amplifier)
this current will always be proportionate to the 'error' signal that is developed by summing of inputs to the amplifier
these will be the demand (+) signal representing the required rpm and (-) feedback signal(s) ie actual rpm and possibly others
the result of summing is a tiny signal representing the difference between the actual rpm and the required rpm
this tiny voltage signal is amplified eg at 30000 Amp/Volt to change the applied current, hence MGUH torque and rpm - continuously
so the motor torque curve obtained if some fixed and arbitrary 'voltage' eg 48V was applied is irrelevant and misleading
the turbo characteristic is not an issue, its just treatable as velocity-related and acceleration-related loads
my guess is that the system could have a bandwidth of maybe 2-3 Hz
so could sweep sinusoidally 0-100000-0 rpm accurately at 1 Hz (and could play tunes such as Renault demonstrated with F1 engines)
so is suitable for most F1 running
of course it can only be as good as the determination of the correct turbo rpm for every moment of competitive ICE running
one would expect also to use eg feedback from pressure sensing
with the fixed fuel rate rules there is less need for boost regulation by wastegate
so regulation by suitably controlled MGUH action must be easier than it would have been in the past
it's 70 years since NACA showed recovery turbines could give 25% more engine efficiency without loss of (combined) power
(but during and after WW2 the customer always preferred to have more combined power without loss of efficiency)
so IMO we're not talking about 'a few drops of fuel'
significant wastegating during recovery would only be helpful if the (electric) recovery was not properly controlled electrically